let user = {
    name: "John",
    age: 30
};

alert(user.name);

alert(user.age);

user.isAdmin = true;

delete user.age;

let user2 = {
    name: "John",
    age: 30,
    "likes birds": true
};

let fruit = prompt('Which fruit to buy?', 'apple');

let bag = {
    [fruit]: 5,
};

alert(bag.apple);

let obj = {}

obj.__proto__ = 5;

alert(obj.__proto__);

for (let key in user) {
    alert(user[key]);
}